Frequency Variation MEP-803A

[gatorbob]

When I startup my MEP-803A with no load and apply different loads, it's impossible to keep it at 60HZ without making manual adjustments.

Is that how it is supposed to work? Is there a maximum variation from 60HZ I should be looking for?

I'm not exactly sure yet where to leave it. I know what the always on load will be but that's pretty low - maybe 1000W. I know what the load will be with the AC running or maybe the water heater. Not sure which amount of load should be tuned for exactly 60HZ.

 

[DieselAddict]

I set mine to about 61.5hz with no load. Fully loaded that gives me just about 60hz.

 

[gatorbob]

I set mine to about 61.5hz with no load. Fully loaded that gives me just about 60hz.

Thanks. I'll try a few different external meters and see if I can get it that close.

 

[jamawieb]

Usually you will get 1-3 drops in hertz. If it drops more, then you need to adjust the governor.

 

[csheath]

Review page 4-15 in TM-9-6115-642-24 for Frequency Droop Adjustment. It will refer you to the performance characteristics on page 1-7.
Here is a print screen for the frequency characteristics.


I tried adjusting mine and couldn't get better than 3% from no load to loaded at 50 amps. I set mine to 62.5 unloaded with a digital meter. There was no change in mine after a couple of turns on the governor screw so I decided to live with it. According to the chart the adjustment range would be 58.2 to 61.8 hz.

 

[Light in the Dark]

Are you basing this solely on what the panel gauge is telling you?

 

[gatorbob]

Are you basing this solely on what the panel gauge is telling you?

. No, the gauge seems to be off/broken. It's off by at least 1 HZ. I was using a Kill-a-Watt device to get readings. I didn't realize I might want to get a permanent frequency/voltage meter now that I see how inexpensive they are.

I also need to adjust my voltage. At first I was set to 111V per leg. My utility power is 123V per leg. While I was out there, I forgot what I was shooting for specifically.

 

[Guyfang]

Bob, one hertz isn't even a measurement. If you are worried about one hertz, go buy a nuke plant. I don't care what you have in the house, nothing will squeal over a one hertz difference. Your house power will fluctuate more then that. Don't go overboard. There are too many other things to worry about.

 

[gatorbob]

The dial is off by 1Hz but that wasn't my problem. My concern is a larger change from idle to full load. I recall it was 3 Hz.

 

[Light in the Dark]

As others have said, you will find to set hertz higher (61.5 is a real good starting point) and give 'her ****, and adjust the hertz once your load has been determined. It should hum there pretty well (even considering tolerance range) for as long as you have fuel.

 

[Light in the Dark]

And yes, most modern power supplies built into products are autoswitchable units (meaning they are universal voltage input, 50/60hz)... so they are gonna run no matter what your MEP throws down the pipe. I routinely see grid power dip to mid 50s for short durations all the time (see it on our large server UPS when I am at work).